The weight gain that most smokers experience following smoking cessation is not only an annoyance, but may increase the likelihood of smoking relapse in some individuals. However, very little research exists on optimal methods of preventing post-cessation weight gain, and, when weight gain occurs, who is most likely to relapse. The purpose of this project is to assess the clinical efficacy of nicotine replacement therapy and dietary management in the prevention of post-smoking cessation weight gain, and to prospectively assess the impact of weight gain on smoking relapse. The studies here proposed will be carried out in the context of a group smoking cessation program and we will manipulate specific treatment components in order to assess their influence on weight gain and smoking relapse. In experimental #1, we will randomly assign subjects to receive on a fixed schedule (q1h) either standard 2 mg or placebo (.5 mg) nicotine polacrilex (Nicorette) while withdrawal, dietary intake, weight gain, and psychosocial variables are assessed. This study should provide valuable information on the efficacy of nicotine replacement on post-cessation weight gain, dietary intake, and relapse rates. In addition, if nicotine replacement does prevent post-cessation weight gain, we will be able to assess whether nicotine replacement simply postpones the weight gain, since we propose assessing dietary intake for a year following the completion of nicotine replacement. In experiment #2, all subjects will be assigned to receive and use 2 mg nicotine polacrilex on the same fixed schedule as in experiment #1; however, just prior to their caloric intake in order to prevent weight gain after the cessation of nicotine replacement. The other half will receive no such training and will continue to eat ad lib. As in study #1, we will assess dietary intake in all subjects through the one year follow-up visit. This study will provide valuable information on the effects of dietary restriction on postcessation weight gain, withdrawal, and smoking relapse - as well as provide new data on the likelihood of compliance with a restricted diet following smoking cessation. The proposed studies should provide new and important information about the prevention of post-smoking cessation weight gain and the effects of weight gain on smoking relapse. In addition, the results of these studies should add to our understanding of the mechanisms contributing to post-cessation weight gain - particularly with regard to nicotine replacement and dietary intake. Finally, the results of this research should have direct applicability in smoking cessation programs: (1) they will be useful in the development of optimal clinical strategies for preventing postcessation weight gain and (2) because the methods employed in these studies are currently commercially available, they will be generalizable to medical practice as well as specific smoking treatment clinics.